A conventional film-forming apparatus of a multi-layered thin film has a configuration in which one sputtering deposition chamber includes sputtering cathodes in a number equal to or more than the number of film types in a multi-layered thin film (refer to Patent Literature 1), or a configuration of a so-called cluster system including plural sputtering deposition chambers each including plural sputtering cathodes (refer to Patent Literature 2).
In another configuration, a cluster system includes sputtering deposition chambers each including one sputtering cathode, at least in a number equal to the number of film types in a multi-layered thin film (refer to Patent Literature 3).
Further, as still another configuration, there is disclosed a sputtering apparatus for depositing a multi-layered film including a magneto-resistance element over a substrate, using a sputtering apparatus including a first vacuum chamber 110 having one target 116a installed therein, a second vacuum chamber 112 having four targets 116b, 116c, 116d and 116e installed therein, and a transfer chamber 114 coupling these two vacuum chambers 110 and 112, as shown in FIG. 8 (refer to Patent Literature 4).
Further, as still another configuration, there will be explained a sputtering system 600 which is disclosed in Patent Literature 5, by the use of FIG. 9. The sputtering system 600 of FIG. 9 includes a first single-target DC magnetron sputtering module 604, a multi-target DC sputtering module 606, a multi-target ion-beam sputtering module 608, and a second single-target DC magnetron sputtering module 610. A load lock 616 enables ingress and egress of a wafer. A control panel 614 controls a parameter and process of the sputtering system 600.
First, by the use of FIG. 10, there will be explained a spin valve sensor 300 which is fabricated by the use of the sputtering system 600 described in FIG. 9. The spin valve sensor 300 described in FIG. 10 includes a substrate 302, a bottom shield layer 311 (Ni—Fe film), a bottom gap layer 304 (Al2O3 film), multiple seed layers 306 (first seed layer: Al2O3 film, second seed layer: Ni—Cr—Fe film, and third seed layer: Ni—Fe film), an anti-ferromagnetic pinning layer 308 (Pt—Mn film), a Co—Fe film 310, a Ru film 312, a Co—Fe film 314, a spacer layer 316 (Cu (Cu—O) film), a Co—Fe film 318, a Ni—Fe film 320, a cap layer 322 (Al (Al—O) film), an upper gap layer 324 (Al2O3 film), and an upper shield layer (Ni—Fe film) 325. Here, FIG. 10 shows that a ferromagnetism sensing layer 307 (called “free layer”) is separated from a ferromagnetic pinned layer 309 by the spacer layer 316. In the spin valve sensor 300 shown in FIG. 10, magnetization of the pinned layer 309 is confined by exchange coupling with an anti-ferromagnetic film called a pinning layer, and magnetization of another ferromagnetic film called a “sensing” layer or a “free” layer 307 is not fixed and rotates freely in response to a magnetic field (signal magnetic field) from a recorded magnetic medium.
Next, by the use of the sputtering system 600 described in FIG. 9, there will be explained a method of fabricating the spin valve sensor 300. First, the bottom gap layer 304 is formed over a wafer in the first single-target DC magnetron sputtering module 604. After that, for stacking the multiple seed layers 306, the wafer is transferred into the second single-target DC magnetron sputtering module 610, and the first seed layer Al2O3 film is stacked. After that, for stacking the second seed layer Ni—Fe—Cr film and the third seed layer Ni—Fe film, the wafer is transferred into the multi-target ion-beam sputtering module 608 and the Ni—Cr—Fe film and the Ni—Fe film are stacked respectively. After that, the wafer is transferred into the multi-target DC magnetron sputtering module 606 for stacking the remaining layers of the spin valve sensor. The remaining layers include the Pt—Mn film 308, the Co—Fe film 310, the Ru film 312, the Co—Fe film 314, the Cu (Cu—O) film 316, the Co—Fe film 318, the Ni—Fe film 320, and the Al (Al—O) film 322. After stacking thereof, the wafer is annealed and a Ta film is stacked.